Aim To determine the sources of stress, its intensity, frequency, and psychophysical and behavioral reactions in physicians working in emergency medical service and those working in health centers. Methods To a convenience sample of primary care physicians employed in emergency medical service (n = 79) and health centers (n = 81), we administered the list of demographic questions, Scale of Sources of Stress, Scale of Intentions of Leaving the Job, and Scale of Psychosomatic Symptoms. Results Emergency medicine physicians experienced significantly more intense and more frequent uncontrollable working situations, conflict between work and family roles, and unfavorable relationships with coworkers than physicians working in health centers. They were also more likely to leave the job during the next few years and/or change jobs within the profession (scores 2.2 ± 0.9 vs 1.7 ± 0.9 out of maximum 5.0, F = 12.2, P = 0.001) and they had a poorer physical health status (scores 1.8 ± 0.5 vs 1.7 ± 0.5 out of maximum 4.0, F = 5.3, P = 0.023). Conclusion Physicians working in emergency medical service experience more stress in almost all aspects of their work than physicians working in health centers. They also have a stronger intention of leaving the job, which decreases with years of experience.